1. Technical Field
The present invention relates to a carrier for manufacturing a printed circuit board (PCB), a method of manufacturing the same, and a method of manufacturing a PCB using the same.
2. Description of the Related Art
Typically, a PCB is manufactured by forming a copper wiring pattern on either or both surfaces of a board made of any type of thermosetting synthetic resin, mounting ICs or electronic components on the board with electrical connections therebetween, and encapsulating the board with an insulating material.
Alongside the recent advancement of the electronics industry is a drastically increasing demand for electronic components having increased functionality which are light, slim, short and small. A PCB which mounts such electronic components is also required to have a high-density wiring pattern and to be slim.
In particular, in order to respond to the reduction in the thickness of a PCB, a coreless substrate is receiving attention, which obviates a need for a core substrate and thus may reduce the total thickness of a PCB and may shorten signal processing time. However, the coreless substrate should include a carrier which serves as a support in the manufacturing process because a core substrate is not used.
FIGS. 1 to 5 sequentially show a process of manufacturing a PCB using a carrier according to a conventional technique. With reference to FIGS. 1 to 5, the method of manufacturing a PCB using a carrier is described infra.
As shown in FIG. 1, a carrier 10 is prepared. Specifically, the carrier 10 is constructed such that an adhesive layer 12, a first metal layer 13 and a second metal layer are sequentially formed on both surfaces of a copper clad laminate 11 including an insulating layer and a copper foil layer formed on both surfaces of the insulating layer. As such, the carrier 10 is hot pressed using a high-temperature and high-pressure press, and thereby both ends of the adhesive layer 12 are adhered to the copper clad laminate 11 and the second metal layer 14. On the other hand, the first metal layer 13 is only in contact with the second metal layer 14, not being adhered to the second metal layer 14.
Next, as shown in FIG. 2, a build-up layer 15 is formed on both surfaces of the carrier 10, and a third metal layer 16 is formed on the outermost insulating layer of the build-up layer 15. Here, the build-up layer 15 may be formed by a method which is typically known in the art, and may be additionally provided with vias for connecting build-up circuit layers thereof. Furthermore, the third metal layer 16 may be provided in order to prevent the warping of the build-up layer 15.
Next, as shown in FIG. 3, the build-up layer 15 is separated from the carrier 10. As such, both ends of the adhesive layer 12, which are adhered to the copper clad laminate 11 and the second metal layer 14, may be removed by a routing process, thereby separating the build-up layer 15 from the carrier 10. The first metal layer 13, which functions as a release layer, is easily separated from the second metal layer 14 after removal of the adhesive layer 12, because the first metal layer 13 is not adhered to the second metal layer 14.
Next, as shown in FIG. 4, the second metal layer 14 and the third metal layer 16 are removed from the build-up layer 15 by etching.
Next, as shown in FIG. 5, openings 17 for exposing pads 19 of the outermost circuit layer of the build-up layer 15 are formed in the outermost insulating layer of the build-up layer 15, and then solder balls 18 are formed on the pads 19.
However, the conventional method of manufacturing a PCB using a carrier is problematic because a vacuum method is adopted in order to make the bonding of the carrier 10 firm or a release layer is additionally formed in order to facilitate the separation of the carrier 10, undesirably increasing process cost and process time.